Preparation / Directions:
Preheat oven to 375. Thaw one puff pastry sheet according to package directions; keep second sheet frozen to use another time. Spread pastry sheet with 1 tablespoon of the mustard; cut in half crosswise.
Cut sausage in half at the curve. Lay one piece of sausage across each piece of puff pastry. Roll pastry around sausage to completely enclose it, taking care to stretch where needed and mold the edges together to seal.
In a small cup, beat egg with milk. Brush pastry with the egg mixture; place on an ungreased rimmed baking sheet. Bake 45-50 minutes, or until browned.
To serve, gently slice each sausage at approximately 2" intervals, alternating the angle of the cuts so each piece has a flat end (on which it will stand) and an angled end (which will be face upward). Garnish by placing about 1/8 teaspoon of the remaining mustard on each piece and topping with chopped chives. Serve hot.
Do Ahead Tip: Prepare wrapped sausages 1 day or several hours before party time and refrigerate until ready to bake..